Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

146 Cards in this Set

  • Front
  • Back
The two sides of the heart are actually two _____ in series with each other.
The left ventricle supplies the ______ circulation at ____ pressure.
The right ventricle supplies the _____ circulation at _____ pressure.
_____ chambers actively pump minor volumes in a resting normal person
The atria have thin wall which are very distensible. They have a large blood capacity. They serve as blood reservoirs for the ventricles, primarily.
They are a low resistance path for blood during passive ventricular filling. ______ pumping role in ventricular filling is important only at high heart rates in normal individuals.
Left ventricular walls are 5-7 times ______ than right ventricular walls
The _____ ventricle is roughly cylindrical, and the _____ ventricle is crescent-shaped when viewed in cross-section. These differences are consistent with differences in pressure development.
Contraction begins in the _____ region of the ventricles and spreads toward the base of the heart, where semilunar valves are located.
The function of the heart is to provide energy for the movement of _____.
In cardiac Valves, normally Only _____ Flow Occurs Through the Valves
Atrioventricular valves include ________ and ______
Mitral and Tricuspid
Normally, valve ____ are not widely separated during ventricular filling.
During ventricular filling, _________ behind cusps, hold them away from the ventricular walls. There is tension on the _______ & _________ and the ________ results in passive ventricular filling.
Eddy currents

Tension of chordae tendineae and papillary muscles.

Funnel effect
Closure of the atrioventricular valves is ________, and is initiated by pressure gradient changes.
Closure of the atrioventricular valves occurs when _____ pressure increases above _______ pressure. This pressure difference forces cusps together. Valve cusps are NOT closed by contraction of papillary muscles.

Papillary muscle contraction during ___________ prevents AV valve cusps from everting into the atria and prevent leakage of blood into the atria (i.e., normally there is no regurgitation).
ventricular systole
Semilunar valves include ______ & _________
(Aortic and Pulmonic)
Normally, eddy currents behind semilunar valve cusps hold them about ________ open during ventricular ejection. (Prevents occlusion of coronary ostia in the aortic root.)
Closure of semilunar valve cusps is _____ and initiated by pressure gradient changes:
When semilunal valves close, _______ pressure falls below that in _____ or _________.

aorta or pulmonary artery
When semilunal valves close, flow of blood is very briefly ______ just outside the semilunar valve, but no significant backleak into the ventricle normally occurs.
When semilunal valves close, valve cusps are held shut during ________ and isovolumic contraction
ventricular diastole
There are ____________ between capillaries and the sarcoplasm or interstitial fluid and sarcoplasm.
Short diffusion distances
cardiac muscle has a very rich _______ supply: about 1 per ______muscle cell.
Cardiac cells are ____ and ____: 5-10 micrometers in radius.
small and thin
T-tubules in mammalian ________ fibers are extensive.
The lumens of T-tubules are open to __________ and contain interstitial fluid.
extracellular space
Branches of T-tubules run ______ and _____, forming a highly ramified, interconnecting network in cardiac muscle.
transversely axially
Functions of T-tubules is facilitation of ______ of ions and molecules between interstitial and intracellular fluids.
They participate in excitation-contraction coupling by rapidly transmitting electrical excitation into the interior of the cells, and providing a source of _______ Ca2+ ions, which cross the cell membranes during phase 2 of fast response action potentials and phase 0 of slow response action potentials.

In cardiac mm, Ca2+ ions that cross the ______ during the action potential cause the release of substantially greater numbers of Ca2+ ions from the __________ (Ca2+ -induced Ca2+ release).
sarcoplasmic reticulum
Cardiac cells are very rich in ________, up to 30% of the cell volume.
Myofibrils in cardiac muscle are similar to those found in skeletal muscles. Thin filaments contain: _____ with ________ & _______.
actin, with tropomyosin and troponin.
Myofibrils in cardiac muscle are similar to those found in skeletal muscles. Thick filaments are made of _____.
Intercalated disks are _______ and _______ connections between adjacent cardiac cells.
Gap junctions are ___ resistance ionic pathways, which allow cell-to-cell spread of depolarization. This does not occur in skeletal muscle.
The __________ for contraction is applicable to cardiac muscle
sliding filament model
In excitation-Contraction Coupling:

1. _______ is conducted over the sarcolemma and into T-tubules.
2. Influx of ________ Ca2+ ions (trigger Ca2+) across both sarcolemma and T-tubule membranes during phase 2 of action potential (via L-type Ca2+ channels, also called dihydropyridine receptors).
3. Release of additional Ca2+ ions from the ___ terminal cisternae through Ca2+ -release channels (also called ryanodine receptors), triggered by events in #2 above (Ca2+-induced Ca2+ release).
4. ________ binds Ca2+ ions.
5. Conformational change occurs in ________ and exposes binding sites for myosin on actin.
6. Crossbridge formation and cycling results in _______ shortening.
1. Action potential
2. extracellular
4. Troponin C
5. tropomyosin
Cardiac relaxation involves:

1. The influx of extracellular Ca2+ ____ as the cell is repolarized.

2. SR actively takes up Ca2+ from the sarcoplasm via ________ pumps.

3. Ca2+ is also extruded from the cell by a _______ and an active ________.

4. _________of troponin I inhibits Ca2+ binding by troponin C. ________ of phospholamban increases Ca2+ uptake by SR via SERCA. (Dephosphorylated phospholamban inhibits Ca2+ uptake by SERCA.)

5. ________ are released and prevented from reforming.

6. _______ again blocks binding sites for myosin on actin.
1. ends

2. sarco-endoplasmic reticulum Ca2+ ATPase (SERCA)

3. sarcolemmal Na-Ca exchanger /Ca2+ ATPase pump



In the whole heart, changes in cardiac muscle fiber length occur with changes in ______ of the heart chambers
In the whole heart, changes in active tension or force development by cardiac fibers result in changes in _________ within the heart chambers
The relationship between __________ and is known as the ________ Starling's Relationship or Frank-Starling Law of the Heart.
systolic pressure
end diastolic volume /
The volume of a cardiac chamber just prior to active muscle contraction determines the _____ for the cardiac fibers in the chamber walls.
On the __________ of the systolic pressure curve (left of the peak of the curve): diastolic sarcomere lengths increase up to about 2.2 microns (2.4 microns in some books) as end diastolic volume increases. Normal ventricles have sarcomere lengths between 1.8 and 2.2 microns, and therefore normally operate on the _________.
ascending limb / ascending limb
At the peak of the systolic curve (peak of the length-active tension curve): the extent of diastolic overlap between thick and thin filaments is thought to reach ______ in normal ventricles.
The _________ of the systolic pressure curve would result from over-distension of the ventricle, resulting in a decrease in systolic pressure development. This does not occur in normal individuals, but can occur in severe heart failure with ventricular dilation.
descending limb
________ on the ascending limb of the systolic pressure curve may occur, in addition to changing amounts of overlap between thick and thin filaments.
Length-dependent activation
Increased sarcomere length may result in greater sensitivity of _________ to calcium ions and greater activation of contractile proteins.
troponin C
Increased cardiac cell length may result in greater increases in ________ concentration in the sarcoplasm after depolarization.
Increased cardiac cell length reduces cell diameter, which may position _____ and ____ filaments closer together laterally, increasing the degree of interaction between them.
The slope of the lower ventricular diastolic pressure vs. end diastolic volume curve is an expression of ventricular wall stiffness. An increase in the slope indicates an increase in ___________. One cause of increased wall stiffness is myocardial hypertrophy.
ventricular wall stiffness
Ventricular wall stiffness is the reciprocal of ventricular _______.
Compliance (C) =
change in volume divided by the accompanying change in pressure.
Therefore, “increased wall stiffness” and “decreased ventricular compliance” both describe changes, which impair _______ filling.
Velocity of muscle fiber shortening is ________ related to the load the muscle must overcome before it can shorten (the afterload, e.g., arterial pressure).
As ___________ increases, greater numbers of crossbridges are required , thus smaller numbers of crossbridges may be available to contribute to fiber shortening. This may partially account for reduced velocity of shortening.
"Vmax” or “(Vo)” is directly proportional to the ____________ of the crossbridges, and occurs when afterload is zero.
maximum rate of cycling
Vmax is directly proportional to _________.
myosin ATPase activity
Po represents the afterload which just exceeds the muscle’s ability to develop enough force to shorten, and velocity will be ______(contraction becomes isometric at this afterload).
Po will increase with increasing _______ on the ascending limb of the Starling curve.
Changes in cardiac __________(inotropy, or inotropic state) affect the relationships above.
Increases in contractility are due to ______ interventions.
positive inotropic
positive inotropic interventions, cause the length-active tension (or diastolic volume-systolic pressure) curve to shift __________
upward and to the left.
positive inotropic interventions, cause the force-velocity curve to shifts _________, with increases in Vmax (Vo) and Po.
upward and to the right
A decreases in contractility is due to __________ interventions. The resulting changes are directionally opposite to the effects in item a above.
negative inotropic
Changes in contractility have an effect on the ____ of ventricular pressure development during ventricular contraction
Maximum _____ of left ventricular pressure development (max dP/dt) is widely used as an index of cardiac contractility.
Max dP/dt is the ____ of the tangent line at the point of maximum rate of change of ventricular pressure during ventricular contraction.
Positive inotropic agents _____ max dP/dt; negative inotropic agents _____ it.
It may be concluded that cardiac contractility has _______, if ventricular peak systolic pressure, Vmax or max dP/dt increase without prior changes in ventricular end diastolic volume or pressure (preload), and if afterload is also constant. Decreases in the 3 variables indicate decreases in contractility.
Increased contractility increases the value of stroke volume/end diastolic volume, or the ______. Decreased contractility does the opposite.
ejection fraction
Increases in end diastolic myocardial fiber length may ________ contractility by the processes of length-dependent activation (see page 6). Decreased fiber lengths result in the opposite effects.
Relaxation properties of the ventricle are referred to as_______properties .
lusitropic (lusitropy),
lusitropy is defined by the end diastolic _____ vs. end diastolic ______ curves for the ventricle
enhanced relaxation; EDP is lower at a given EDV. The curve is shifted downward. Ventricular filling is facilitated.
Positive lusitropy
inhibited relaxation; EDP is higher at a given EDV. The curve is shifted upward. Ventricular filling is impaired.
Negative lusitropy
Important Basic Concepts in THE CARDIAC CYCLE

1. Electrical events _______ mechanical events.
2. Atrial contraction _____ ventricular contraction.
3. Blood flows from areas of high energy to areas of ___ energy.
4. Cardiac valves maintain_________ flow.
5. In ventricular ______ , no blood flows from ventricle into aorta or pulmonary artery.
6. During most of ventricular diastole, intraventricular pressure is normally very ____ (only 0-7 mmHg).
1. precede
3. low
4. unidirectional
5. diastole
6. low
Atrial Systole occurs during ventricular _____
During atrial systole, small ______ occur in both atrial and ventricular pressures.
During atrial systole, only a small increase occurs in ventricular _____: "atrial kick".
____ atrial systole produces the "a" wave in the jugular venous pressure record.
During atrial systole, ventricles begin to depolarize during the ___ waves on electrocardiogram.
During atrial systole, ___ heart sound occurs.
Completion of ventricular depolarization occurs with the ___ waves.
During ventricular Systole, Intraventricular ______ increases very rapidly.
During ventricular Systole, ventricular ______ does not change.
During ventricular Systole, _____ valves bulge into the atria, slightly increasing atrial and venous pressures
During ventricular Systole, Initial component of ____ heart sound occurs.
During Rapid Ventricular Ejection, Ventricular _____ decreases rapidly.
1) Cardiac muscle fibers shorten.
2) Aortic blood flow increases rapidly to a peak.
3) Greatest velocity of cardiac fiber shortening occurs.
Rapid Ventricular Ejection
During Rapid Ventricular Ejection, Base of the heart moves toward the apex. Atria are stretched, causing atrial pressure to ______ slightly.
During Rapid Ventricular Ejection, Ventricular and aortic ______ both increase to peak values.
During Rapid Ventricular Ejection, ___ wave of jugular venous pulse occurs.
During Rapid Ventricular Ejection, Second component of ____ heart sound occurs.
When ther is reduced Ventricular Ejection, Ventricular volume decreases more ____.
When ther is reduced Ventricular Ejection, Aortic blood flow is _____, but is not zero.
On EKG Ventricular repolarization is signified by a ___ wave.
Ventricular Diastole is _____________
Isovolumic Relaxation
_______ valves close at the very beginning of Ventricular Diastole
In Ventricular Diastole, Incisura (dicrotic notch): aortic pressure increases slightly following _____ valve closure.
In Ventricular Diastole, Intraventricular pressure _____ very rapidly.
In Ventricular Diastole, Ventricular ______ does not change.
In Ventricular Diastole, Progressive ______ in atrial and venous pressures continue.
In Ventricular Diastole, ____ heart sound occurs immediately following semilunar valve closure.
During Rapid Ventricular Filling, Ventricular filling is _______.
During Rapid Ventricular Filling, Both ventricular and atrial pressures ______.
During Rapid Ventricular Filling, Jugular venous pressure _____.
During Rapid Ventricular Filling, ____ heart sound occurs.
Reduced Ventricular Filling is also called ______.
During Reduced Ventricular Filling, Ventricular volume increases more slowly, and filling is ______.
Reduced Ventricular Filling, is the first part of the cycle to be shortened when heart rate ______.
During Reduced Ventricular Filling, ______ depolarize (P wave).
Aortic blood flow = flow through the _____, not in distal aortic segments.
aortic valve
________ is the volume of blood ejected by each ventricle during each cardiac cycle.
Stroke Volume (SV)
SV =
EDV - ESV, where

EDV = ventricular end diastolic volume
ESV = ventricular end systolic volume
________ is the volume of blood ejected by each ventricle per minute.
Cardiac Output (CO)
CO =
SV x HR, where

HR = heart rate/ minute
Under ______ conditions, left ventricular SV and CO equal right ventricular SV and CO. Transient inequalities do occur, but control mechanisms quickly restore the balance.
steady state
approximately the total blood volume. (e.g., about 5 liters per minute for an "average" 70 kg adult male.)
Resting CO:
________ is the total work done per cardiac cycle
Stroke Work (SW)
SW =
(pressure-volume work + kinetic work)
Pressure-volume work =

where P = mean pressure during ejection
KW is work required to ______ the blood during ejection.
KW =

where m = mass of blood
v = linear velocity
At rest, KW is negligible compared to ______ .
_____ is the work performed by the ventricle each minute
Minute Work (MW)
MW =
P·SV·HR where HR = heart rate (per minute).
SV·HR = ____
Mean arterial pressure (MAP) is usually used as P when MW for the left ventricle is being calculated:
MW (left ventricle)=
Myocardial Oxygen Consumption (MVO2) will roughly ______ if MAP is doubled from 80 to 160 mm Hg while CO is held constant (increased pressure work).
Myocardial Oxygen Consumption (MVO2) will _________if CO is doubled from 17 to 34 liters/hr while MAP is held constant (increased volume work).
increase relatively slightly
Myocardial Oxygen Consumption (MVO2) of the LV is directly proportional to the product of ________ and the _________.
average LV ejection pressure

duration of ejection
Myocardial Oxygen Consumption (MVO2) of the LV is directly proportional to the product of ______ and __________(this is sometimes called the “double product”).
heart rate
systolic arterial pressure
Cardiac Efficiency (CE)=
cardiac work/energy utilized x 100
As a pump, a normal heart is approximately ___ efficient.
CE will usually _____ if MAP increases and CO is held constant.
CE will usually _____ if CO increases and MAP is held constant.
RELATIONSHIP BETWEEN __________ AND __________ (assumes the ventricle is shaped as a sphere)is explained by Law of Laplace
T =

where T = wall tension (or wall stress)

P = intraventricular pressure
r = ventricular radius (from midchamber to midwall)
w = wall thickness
Wall tension during _____ is the magnitude of the load on ventricular muscle fibers (i.e., another expression of afterload), and changes during systole.
MVo is directly ______ to wall tension during systole.
A dilated ventricle has a _____ MVo2 and a _____ efficiency than a normal one.
Major causes of vibrations in the cardiovascular system:
1. ___________ of blood.
2. _____ occurring during rapid blood flow.
1.Acceleration and deceleration
The 1st heart sound:

1.Occurs during isovolumic ______ .
2. Blood accelerates toward _____, but the A-V valves close, and blood decelerates.
3. Vibrations are set up in ________, _____, & _______ .
4. Part of the first sound may also be due to blood moving into the ________, distending the vessels and producing vibrations in them during rapid ejection.
1. contraction
2. atrium
3. blood, valves and ventricular walls
4. pulmonary artery and aorta
The 2st heart sound:

1. Occurs during isovolumic ______ .
2. Closure of ______ valves causes deceleration of blood.
3. Vibrations are set up in the ______, ______, ______, & _______.
1. relaxation
2. semilunar
3. valve cusps, aorta, pulmonary artery and ventricular chambers.
Third Heart Sound:
1. Occurs during ___________.
2. Movement of blood from atria into ventricles produces vibrations of the ________ .
3. This sound is usually _______with a stethoscope in normal adults (exceptions may occur). May be heard in some normal children.
4. Cardiac _______ may result in an audible third sound.
1. rapid ventricular filling
2. chamber walls
3. inaudible
4. abnormalities
Fourth Heart Sound (also called the atrial sound):
1. Occurs during ________.
2. Movement of blood from atrium into the nearly full ______ produces low frequency and amplitude vibrations.
3. Usually detectable only with a phonocardiogram in _____ individuals (exceptions may occur).
4. Cardiac _______ may result in an audible fourth sound.
1. atrial systole
2. ventricle
3. normal
4. abnormalities